The present invention relates to a vacuum pump, comprising at least one pump chamber and at least one chamber for a motor, drive, gear, crankshaft or the like, adjoining said pump chamber.
In many branches of industry, vacuum pumps of the kind affected here need to pump etching and/or toxic gases. These gases may enter into chambers adjoining the pump chambers, said chambers being generally separated by seals (shaft seals, labyrinth boxes etc.) from the pump chambers. Etching gases give rise to corrosion or abrasions in these chambers, resulting in premature wear of the bearings or damage to other components located therein. Moreover, etching or toxic gases may pass through the chambers adjoining the pump chamber into the atmosphere. In the semiconductor industry, the demand for dry vacuum pumps, i.e. vacuum pumps which are free of oil at least with respect to their pump chamber, is ever increasing. The reason for this is, that the processes which are performed in vacuum chambers to which the vacuum pumps are connected, need to be protected against interfering hydrocarbons. The gases forming or employed in the semiconductor industry pumped by the vacuum pump often have the property of forming solids while they are being compressed to atmospheric pressure. Also deposits of this kind may cause harm in the chambers adjoining the pump chamber.